1. Field of the Invention
The present invention relates generally to disposable beverage container lids which may be secured to the rim of a beverage container to prevent spillage and inhibit heat gain or loss. More particularly, the present invention relates to such container lids which include a tear strip or flap which may be folded back to allow drinking from the container without removing the container lid.
2. Description of the Prior Art
Beverage container lids adapted to fasten over the rim or lip of disposable beverage containers are well known. Such lids prevent spillage and evaporation of the beverage within the container, and help insulate the contents of the container from the ambient temperature. In their most simple form, such beverage container lids comprise a generally flat lid surface in the form of disk having a peripheral sealing skirt for securing the lid to the rim of a beverage container. While such lids are entirely suitable for the purposes just described, they must be completely removed in order to gain access to the contents of the container.
Improved beverage container lids which include an openable tear strip or flap have been devised. See, for example, U.S. Pat. Nos. 3,977,559, 4,090,660, and 4,210,272. Such modified beverage container lids offer the advantage of allowing limited access to the contents of the container while still covering most of the open end of the container. Thus, a user is able to drink from the cup while the spillage-prevention and insulation afforded by the lid are still largely maintained. Such lids, however, suffer from the disadvantage that the tear strip, once opened, is unsecured and will often interfere with the user drinking from the cup.
Further improvements have been made to the beverage lid containers including fold-back flaps. Various means have been provided for securing the tear strip or flap in its fully folded back configuration. For example, U.S. Pat. No. 3,994,411 discloses a container lid having a fold-back flap which includes a pull tab along its outermost edge. The pull tab may be inserted into a slit along the outermost edge of the lid to hold the flap in its fully opened position. U.S. Pat. No. 4,202,459 discloses an embossed slot formed on the upper surface of the lid which is able to receive the peripheral skirt of the lid when the flap is fully folded back. Finally, U.S. Pat. No. 4,322,015 discloses a container lid having a fold-back flap which is secured by one or more retainer studs which project upward from the upper surface of the lid. Although each of these designs is workable, the openable flaps frequently become dislodged from their containing means. Moreover, it is frequently necessary to employ relatively heavy gauge (stiff) materials in order to achieve a highly reliable fastening system.
For the above reasons, it would be highly desirable to provide a beverage container lid which includes an improved means for fastening an openable access flap in its fully opened position. In particular, it would be desirable to provide such a flap which may be stored in a manner which is flush with the upper surface of the beverage container lid.